Consider the substitution reaction that rakes place when (R)-3-bromo 3-methylhexane is treated with methanol. Which of the following would be true? The reaction would take place only with inversion of configuration at the center. The reaction would take place only with retention of configuration at the center. The reaction would take place with racemization. No reaction would take place. The alkyl halide does not possess a center.

The reaction would take place with racemization.

Explanation:

The compound (R)-3-bromo 3-methylhexane contains has the leaving group attached to a tertiary carbon atom. When the leaving group is attached to a tertiary carbon atom, the compound undergoes nucleophilic substitution via SN1 mechanism. This mechanism involves the formation of a planar carbocation intermediate. The nucleophile may attack this intermediate from either faces, leading to racemization of the product.

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol

the objects have the same charge is correct.

nathan lee